Could Putin be tried for the crime of aggression?

Derrick Wyatt explores whether the Presidents of Russia and Belarus could be tried in international law for the crime of aggression, concluding that it would be legally possible but lack credibility.

Published by UK in a Changing Europe here.

On the face of it, Russia and Belarus have violated the UN Charter’s prohibition on the use of force by collaborating in a large-scale invasion of Ukraine, and their leaders have committed the international crime of aggression.

War crimes and crimes against humanity appear to have been committed in the course of the invasion, including murder and rape, and the extensive and unjustified destruction of civilian property. These are crimes more readily laid at the door of the military than heads of state and government, whose complicity might either be lacking, or impossible to prove.

There have been calls for President Putin, perhaps along with President Lukashenko of Belarus, to stand trial before a special tribunal, charged with the crime of aggression against Ukraine. These calls have come from various sources, including the Ukrainian Government,  the EU, and the Parliamentary Assembly of the Council of Europe.

The International Criminal Court has authority to try individuals for war crimes and the crime of aggression, but that authority is limited in two respects relevant here. The first is that its rules prohibit trying defendants in their absence. The second is that it can only try an individual for the crime of aggression if they are a national of a state that has signed up to the Court’s statute. That rules out such proceedings against Presidents Putin and Lukashenko because neither Russia nor Belarus have done so. 

That explains why the search is on for an alternative judicial process to measure the guilt or innocence of those alleged to be criminally responsible for the war against Ukraine. That process would have to be legally and politically credible. There are several obstacles to it being so.

One is that international law shields heads of state and other high officials, as long as they are in office,  both from the reach of national and international courts - unless the latter can be said to acting on behalf of the international community as a whole. But even an international court can  only override the immunity of a serving head of state if the state in question is legally bound to respect the authority of the court. For the heads of states which have signed up to the tribunal in question there is no problem. The problem lies with countries which have not done so and object to purported changes in the law which would deprive them of their existing immunities. Russia and Belarus will not volunteer to give up their immunities anytime soon.

The second obstacle to establishing a credible judicial process to try national leaders for aggression against Ukraine is that international law shields heads of state and government from trial for the crime of aggression even after they have left office. The authoritative International Law Commission has said that former heads of state might be tried before foreign courts for war crimes and crimes against humanity, but neither of these categories covers the crime of aggression. The omission of aggression as an exception to immunity cannot be dismissed as being technical or accidental. Some governments have understandable reservations about empowering national courts and ad hoc international tribunals to prosecute heads of state for military operations they have authorised on the say so of countries which might turn out to be their opponents and adversaries.

There is however, one judicial system which does appear to have the legal authority to override the immunities of Presidents Putin and Lukashenko. That judicial system is that of Ukraine. Ukraine has criminalised aggression under its Criminal Code, and has announced that it has opened an investigation. The legal argument for Ukraine being able to overrule the immunities of the leaders of Russia and Belarus is that Ukraine has been released from its obligations to grant immunity to these leaders by their unlawful aggression against Ukraine. This is a credible legal argument. It supports the position of governments, including that the UK, which are assessing the feasibility of a new ‘hybrid’ tribunal, which would be, according to the UK Government,  “a specialised court integrated into Ukraine’s national justice system with international elements.”

A trial of the Presidents of Russia and Belarus before such a “hybrid” tribunal would inevitably be held in the absence of the defendants (in absentia). This would not be a legally insurmountable problem, since neither the International Covenant on Civil and Political rights nor the European Convention on Human Rights prohibit trials in absentia, but it would leave the proceedings vulnerable to the criticism that they prejudiced the rights of defendants. International tribunals such as the International Criminal Court prohibit trial in the absence of the defendant with only very limited exceptions. Trials in absentia are exceptional in the UK, but may be permitted where a defendant refuses to participate. In a recent case a US citizen accused of causing death by careless driving in the UK, who had refused to return to the UK, was tried and convicted in the UK in her absence, though she participated via a video link. One difficulty with a trial on such a basis is that a defendant can simply switch off the link, and the court has no control over the proceedings.

A trial of the Presidents of Russia and Belarus in which those leaders remained conspicuously at large would lack credibility. The Presidents would deny the authority of the tribunal to try them, accuse the tribunal’s judges of bias, and portray the trial as being a weapon in NATO’s proxy war against Russia rather than genuine judicial proceedings. These criticisms might strike chords even with some of the countries critical of the invasion of Ukraine.

Those governments, like that of the UK, which are considering the feasibility of setting up a tribunal to ensure criminal accountability for the invasion of Ukraine, might find that they have embarked on mission impossible.